Grinding device for revolving cutters



June 18, 1935. R. DIM DONALD I GRINDING DEVICE FOR REVOLVING CUTTERS Filed July 7, 1934 Patented June 18, 1935 UNITED STATE GRINDING DEVICE FOR REVOLVING CUTTERS Raymore D. MacDonald, Western Springs, 111., assignor to International Harvester Company, a corporation of New Jersey Application July 7, 1934, Serial No.,'734,122

' 4 Claims.

This invention relates to a knife grinding device.

More specifically it relates to a knife grinding attachment for machines having a rotor which carries cutting blades.

The principal object of the present invention is to devise and construct a knife grinding attachment particularly adapted for sharpening the blades of a rotary cutter without removing the rotor or the blades from the machine of which it is a part.

expensive grinding element.

Another object is to provide a grinding device which is particularly adapted for grinding blades of rotors of spiral or other shape which describe intheir rotation a surface of revolution, whereby the stone may be reciprocated to cover the entire edges of the blades which lie in the surface of revolution.

These objects and others which will be apparent from the detailed description to follow are accomplished by a device as illustrated in the drawing when utilized as set forth in the description of the operation which follows.

In the drawing:

Figure 1 is a cross section through a casing in which a rotor is mounted for operation and on tion has been. mounted;

which a grinding device embodying the inven- Figure 2 is a side elevation of the construction shown in Figure 1, illustrating particularly the grinding device; and,

Figure 3 is a detail view of the supporting means for the grinding device on the rotor supporting casing.

As this invention relates only to the knife or blade sharpening device, only a portion of a casing H) has been shown. This casing may be a part of any material reducing means, such as an ensilage harvester or cutter, or other feed reducing means. A rotor H is mounted in the casing If) on a transverse shaft 12, means not shown being provided for rotating the shaft II. The rotor Ill carries at its periphery spiral blades I3 which are rigidly secured in position by bolts l4. These spiral blades are so shaped that during rotation their cutting edges [5 generate in a geometric sense a cylinder of revolution.

For

certain particular purposes it might be found advisable in machines of this nature to arrange straight or spiral blades, the cutting edges of which would generate conicalsurfaces of revolution during operation. This point is mentioned, as the grinding attachment may be utilized equally well on rotors, the blades of which follow either conical or cylindrical surfaces.

On the parallel side walls It of the casing I!) brackets [l are pivoted on a transverse axis parallel to a line lying in the surface of revolution defined by the knife edges i5. In the embodiment illustrated the brackets are pivoted on an axis parallel to the axis of the shaft 12, and likewise the other parts to be hereinafter described will be parallelto this axis.

Two slide bars l8 are secured in spaced relation to the brackets Ill, said bars being parallel to each other and parallel to the axis of the shaft H2. The barsland the brackets ll provide a pivotally mounted supporting frame on which a supporting structure l9 for the grinding element is slidably mounted. As shown in Figure 3, alternate ends of the bars H are secured to the respective bracket H, the other ends being slidably mounted in the bracket. This construction provides for easy removal of the supporting frame and of the grinding stone support therefrom.

' The structure l9 consists of a center member 20 provided with bearing portions 2|, which slidably engage the bars l8 and a pair of bearing caps 22, which, with the bearing portions 2!, form a slidable mounting for the supporting .structure on the cross bars Hi. The caps 22 are secured by cap screws to the member 20.

A cup-like portion 23 of the center member 20 is formed to receive a suitable grinding stone 24, which is rigidly secured in the pocket. Said stone is provided with a flattened face to engage the edges E5 of the blades 13 as they are rotated about their supporting axes. As the supporting structure i9 is reciprocated transversely of the bars l8 the grinding stone 24 traverses the entire edges of the blades 93, it being understood that the rotor is in motion during reciprocation of the grinding stone.

To provide means for holding the supporting frame resiliently in position, two threaded members 25, pivoted on the side walls N3 of the easing, extend through openings 26 formed in right angled extensions of the brackets ll. Springs 2'! abut the members 25 adjacent their pivotal connections at one end and abut the inside portion of the brackets ll at their other end.

Springs 28, which are relatively stronger than the springs 21, abut the outer sides of the brackets I! at one end and abut a threaded hand nut 29 at their other end. Spring held latches 30 mounted on the brackets ll engage suitable notches 3| in the hand nuts 29 for holding said nuts against turning during vibration incident to operation of the grinding device.

The supporting brackets I! are mounted, as previously described, to provide with the bars 18 a slidable support for the grinding element supporting structure IS. The upper end of the pivoted brackets ll are resiliently held in position by the springs 27 and 28. By providing the springs 28 stronger than the springs 21, the grinding stone may be tilted toward the rotor by tightening the hand nuts 29. There is sufiicient flexibility in the connections of the bars l8 with the brackets H to permit slight relative angular movement of the backets H by adjusting only one of the hand nuts 29. By this means the guide bars i 8 may be adjusted to bring movement of the stone 24 into a parallel line with the contact line in the surface of revolution generated by the knife edges I5.

To provide meansv for readily reciprocating the grinding stone supporting structure IS, a rod 32 secured to the structure extends laterally through an opening in the side wall l6 and is provided at its outer end with a bent down portion which may be grasped by the operator. By the provision of this means the grinding stone support may be readily reciprocated over the surface of the rotor during rotation thereof, whereby the edges of all of the blades may be engaged and sharpened.

It is to be understood that applicant has shown and described only a preferred embodiment of his knife grinding attachment for the blades of rotors, and that he claims as his invention all modifications falling within the scope of the appended claims.

What is claimed is:

l. A sharpening device for a material reducing machine having a supporting structure, a rotor mounted for rotation thereon, and blades mounted on the rotor positioned with their cutting edges following a cylindrical path, and in combination therewith; a supporting frame pivotally mounted on the supporting structure on an axis parallel to the axis of the rotor, a support mounted for reciprocation on said frame, a grinding stone carried by said support, means for reciprocating the support whereby the stone is moved along the cylinder of revolution defined by the edges of the blades, and manually adjustable resilient means for holding the supporting frame in position and for urging the frame toward the cutting blades.

2. A sharpening device for a material reducing machine having a casing, a rotor mounted for rotation in the casing, and blades mounted on the rotor positioned with their cutting edges following a cylindrical path, and in combination therewith; two spaced brackets pivotallymounted on an axis parallel to the axis of the rotor, supporting bars secured to the respective brackets at one of their ends and slidably carried at their other ends by the other brackets, said bars being parallel to the axis of the rotor, a support mounted for reciprocation on said bars, a grinding stone carried by said support, and means for reciprocating the support whereby the stone is moved along the cylinder of revolution defined by the edges of the blades.

3. A sharpening device for a material reducing machine having a casing, a rotor mounted for rotation in the casing, and blades mounted on the rotor positioned with their cutting edges following a cylindrical path, and in combination therewith; two spaced brackets pivotally mounted on an axis parallel tothe axis of therotor, two spaced supporting bars mounted on said brackets parallel to the axis of the rotor, a support mounted for reciprocation on said bars, a grinding stone carried by said support, means for reciprocating the support whereby the stone is moved along the cylinder of revolution defined by the edges of the blades, and resilient, manually adjustable means for holding the brackets in position and for urging the brackets toward the rotor and the grinding stone carried thereby against the cutting edges of the blades.

4. A sharpening device for a material reducing machine having a casing, a rotor mounted for rotation in the casing, and blades mounted on the rotor'positioned with their cutting edges followinga cylindrical path, and in combination therewith; two spaced brackets pivotally mounted on an axis parallel to the axis of the rotor, two spaced supporting bars mounted on said brackets parallel to the axis of the rotor, each of said bars being slidable with respect to one bracket to facilitate removal, a support mounted for reciprocation on said bars, a. grinding stone carried by said support, means for reciprocating the support whereby the stone is moved along the cylinder of revolution defined by the edges of the blades, and resilient, manually adjustable means for holding the brackets in position and for urging the brackets toward the rotor and the grinding stone carried thereby against the cutting edges of the blades.

RAYMORE D. MACDONALD. 

